There is a continual need for bactericidal materials and, in particular, it is desirable to have bactericides which inhibit Streptococcus mutans which is the principle cariogenic bacterium responsible for the formation of dental plaque. Dental plaque can give rise to caries, calculus, or inflammatory changes in adjacent tissue.
Beta-diketones are known particularly for their ability to chelate with various metals. It has been proposed to produce dental compositions containing complexes of 1,1,1-trifluoropentan-2,4-dione or 1,1,1,5,5,5-hexafluoropentan-2,4-dione with zinc, copper (II) or zirconium as described in British Patent Specification No. 1,319,247 and French Patent Application Ser. No. 2,088,370. These patents teach that mineralization of plaque into calculus can be inhibited using such compounds. Republic of South Africa Patent Application Ser. No. P 72/25921 teaches that zinc and copper complexes of certain betadiketones are useful in preventing tooth discoloration and tartar deposit. U.S. Pat. No. 4,015,980 teaches that zinc is extracted from aqueous ammoniacal solutions using certain .beta.-diketones, and U.S. Pat. No. 2,856,418 discloses a process for separating plutonium from an aqueous solution of its tetravalent salt using certain fluorinated .beta.-diketones.